I installed a pair of 18" Nitto 555R 285/35/18 for occasional drag racing purposes. I notice that the outer 2cm or even more of the tire width is not used. When I did the alignment, the guys from the shop said that camber setting is at the limit and all they could do is 1.2 degrees of camber, they can't do less.

Is there an adjustment that they can use to dial in less camber in the rear ? Or maybe I am thinking it completely wrong and the car would become unstable anyway with less camber ?